POLISHING PAD AND METHODS OF IMPROVING PAD REMOVAL RATES AND PLANARIZATION

摘要

A method of improving a removal rate of a pad includes producing a body of a pad of polyurethane from a mix; and introducing into the mix an additive which decreases an elastic rebound of the pad so as to increase a chemical-mechanical planarization removal rate; and using as the additive a substance which at least contains starch. In another embodiment, planarization of urethane polishing pads is improved by combining a base resin and an isocyanate to form a pad, wherein the isocyanate has a concentration of 6.5 to about 11.0 weight percent of the base resin. In another embodiment, in a CMP process that includes removing a barrier and buffing a polyurethane after a bulk copper removal process, a polishing pad is used having a shore D hardness less than 35% and having at least one layer made from a mix composed of at least one of a prepolymer with an isocyanate concentration of between 6.5% and 11.0% to achieve a molal concentration, and a monomer in combination with an addition of isocyanate to achieve the substantially same molal concentration.